CliffsStudySolver Trigonometry
Chapter One
Trigonometric Ideas
The word trigonometry comes from two Greek words, trigonon, meaning triangle, and
metria, meaning measurement. This is the branch of mathematics that deals with the ratios
between the sides of right triangles with reference to either of its acute angles and enables
you to use this information to find unknown sides or angles of any triangle. Trigonometry is not
just an intellectual exercise, but has uses in the fields of engineering, surveying, navigation,
architecture, and yes, even rocket science.
Angles and Quadrants
An angle is a measure of rotation and is expressed in degrees or radians. For now, we'll stick
with degrees, and we'll examine working with radians in the next chapter. Consider any angle
in standard position to have its vertex at the origin (the place where the x- and y-axes cross),
labeled O in the diagrams. Angle measure is the amount of rotation between the two rays forming
the angle.
Figure the initial side of the angle above beginning on the x-axis to the right of the origin.
Consider the terminal side of the angle to be hinged at O. The terminal side of the angle, OP,
was rotated ... read full excerpt from CliffsStudySolver Trigonometry ebook
